For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological...For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological index(RSEI)was calculated for the Lijiang River Basin in Guangxi Zhuang Autonomous Region for 1991,2001,2011,and 2021.Spatial autocorrelation analysis was employed to investigate spatiotemporal variations in the ecological environmental quality of the Lijiang River Basin.Furthermore,geographic detectors were used to quantitatively analyze influencing factors and their interaction effects on ecological environmental quality.The results verified that:1)From 1991 to 2021,the ecological environmental quality of the Lijiang River Basin demonstrated significant improvement.The area with good and excellent ecological environmental quality in proportion increased by 19.69%(3406.57 km^(2)),while the area with fair and poor ecological environmental quality in proportion decreased by 10.76%(1860.36 km^(2)).2)Spatially,the ecological environmental quality of the Lijiang River Basin exhibited a pattern of low quality in the central region and high quality in the periphery.Specifically,poor ecological environmental quality characterized the Guilin urban area,Pingle County,and Lingchuan County.3)From 1991 to 2021,a significant positive spatial correlation was observed in ecological environmental quality of the Lijiang River Basin.Areas with high-high agglomeration were predominantly forests and grasslands,indicating good ecological environmental quality,whereas areas with low-low agglomeration were dominated by cultivated land and construction land,indicating poor ecological environmental quality.4)Annual average precipitation and temperature exerted the most significant influence on the ecological environmental quality of the basin,and their interactions with other factors had the great influence.This study aimed to enhance understanding of the evolution of the ecological environment in the Lijiang River Basin of Guangxi Zhuang Autonomous Region and provide scientific guidance for decision-making and management related to ecology in the region.展开更多
A highly flexible and continuous fibrous thermoelectric(TE)module with high-performance has been fabricated based on an ultra-long single-walled carbon nanotube fiber,which effectively avoids the drawbacks of traditio...A highly flexible and continuous fibrous thermoelectric(TE)module with high-performance has been fabricated based on an ultra-long single-walled carbon nanotube fiber,which effectively avoids the drawbacks of traditional inorganic TE based modules.The maximum output power density of a 1-cm long fibrous TE module with 8 p–n pairs can reach to 3436μW·cm^(-2),the power per unit weight to 2034μW·g^(-1),at a steady-state temperature difference of 50 K.The continuous fibrous TE module is used to detect temperature change of a single point,which exhibits a good responsiveness and excellent stability.Because of its adjustability in length,the flexible fibrous TE module can satisfy the transformation of the temperature difference between two distant heat sources into electrical energy.Based on the signal of the as-fabricated TE module,a multi-region recognizer has been designed and demonstrated.The highly flexible and continuous fibrous TE module with excellent performance shows a great potential in diversified applications of TE generation,temperature detection,and position identification.展开更多
Lithium–sulfur（Li–S） batteries have received more and more attention because of higher specific capacity and energy density of sulfur than current lithium–ion batteries. However, the low electrical conductivity o...Lithium–sulfur（Li–S） batteries have received more and more attention because of higher specific capacity and energy density of sulfur than current lithium–ion batteries. However, the low electrical conductivity of sulfur and its discharge product, and also the high dissolution of polysulfides restrict the Li–S battery practical applications. To improve their performances, in this work, we fabricate a novel free-standing, curled and partially reduced graphene oxide（CPrGO for short） network and combine it with sulfur to form a CPrGO–S composite as a cathode for Li–S battery. With sulfur content of 60 wt%, the free-standing CPrGO–S composite network delievers an initial capacity of 988.9 m Ah·g^（-1）. After 200 cycles,it shows a stable capacity of 841.4 m Ah·g^（-1） at 0.2 C, retaining about 85% of the initial value. The high electrochemical performance demonstrates that the CPrGO–S network has great potential applications in energy storage system. Such improved properties can be ascribed to the unique free-standing and continous CPrGO–S network which has high specific surface area and good electrical conductivity. In addition, oxygen-containing groups on the partially reduced graphene oxide are beneficial to preventing the polysulfides from dissolving into electrolyte and can mitigate the ＂shuttle effect＂.展开更多
基金supported by the Guangxi Natural Science Foundation(2020GXNSFAA297266)Doctoral Research Foundation of Guilin University of Technology(GUTQDJJ2007059)Guangxi Hidden Metallic Mineral Exploration Key Laboratory。
文摘For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological index(RSEI)was calculated for the Lijiang River Basin in Guangxi Zhuang Autonomous Region for 1991,2001,2011,and 2021.Spatial autocorrelation analysis was employed to investigate spatiotemporal variations in the ecological environmental quality of the Lijiang River Basin.Furthermore,geographic detectors were used to quantitatively analyze influencing factors and their interaction effects on ecological environmental quality.The results verified that:1)From 1991 to 2021,the ecological environmental quality of the Lijiang River Basin demonstrated significant improvement.The area with good and excellent ecological environmental quality in proportion increased by 19.69%(3406.57 km^(2)),while the area with fair and poor ecological environmental quality in proportion decreased by 10.76%(1860.36 km^(2)).2)Spatially,the ecological environmental quality of the Lijiang River Basin exhibited a pattern of low quality in the central region and high quality in the periphery.Specifically,poor ecological environmental quality characterized the Guilin urban area,Pingle County,and Lingchuan County.3)From 1991 to 2021,a significant positive spatial correlation was observed in ecological environmental quality of the Lijiang River Basin.Areas with high-high agglomeration were predominantly forests and grasslands,indicating good ecological environmental quality,whereas areas with low-low agglomeration were dominated by cultivated land and construction land,indicating poor ecological environmental quality.4)Annual average precipitation and temperature exerted the most significant influence on the ecological environmental quality of the basin,and their interactions with other factors had the great influence.This study aimed to enhance understanding of the evolution of the ecological environment in the Lijiang River Basin of Guangxi Zhuang Autonomous Region and provide scientific guidance for decision-making and management related to ecology in the region.
基金the National Key Research and Development Program of China(Grant No.2018YFA0208402)the National Natural Science Foundation of China(Grant Nos.11634014,51172271,and 51372269)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA09040202)。
文摘A highly flexible and continuous fibrous thermoelectric(TE)module with high-performance has been fabricated based on an ultra-long single-walled carbon nanotube fiber,which effectively avoids the drawbacks of traditional inorganic TE based modules.The maximum output power density of a 1-cm long fibrous TE module with 8 p–n pairs can reach to 3436μW·cm^(-2),the power per unit weight to 2034μW·g^(-1),at a steady-state temperature difference of 50 K.The continuous fibrous TE module is used to detect temperature change of a single point,which exhibits a good responsiveness and excellent stability.Because of its adjustability in length,the flexible fibrous TE module can satisfy the transformation of the temperature difference between two distant heat sources into electrical energy.Based on the signal of the as-fabricated TE module,a multi-region recognizer has been designed and demonstrated.The highly flexible and continuous fibrous TE module with excellent performance shows a great potential in diversified applications of TE generation,temperature detection,and position identification.
基金supported by the National Basic Research Program of China(Grant No.2012CB932302)the National Natural Science Foundation of China(Grant Nos.11634014,51172271,and 51372269)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA09040202)
文摘Lithium–sulfur（Li–S） batteries have received more and more attention because of higher specific capacity and energy density of sulfur than current lithium–ion batteries. However, the low electrical conductivity of sulfur and its discharge product, and also the high dissolution of polysulfides restrict the Li–S battery practical applications. To improve their performances, in this work, we fabricate a novel free-standing, curled and partially reduced graphene oxide（CPrGO for short） network and combine it with sulfur to form a CPrGO–S composite as a cathode for Li–S battery. With sulfur content of 60 wt%, the free-standing CPrGO–S composite network delievers an initial capacity of 988.9 m Ah·g^（-1）. After 200 cycles,it shows a stable capacity of 841.4 m Ah·g^（-1） at 0.2 C, retaining about 85% of the initial value. The high electrochemical performance demonstrates that the CPrGO–S network has great potential applications in energy storage system. Such improved properties can be ascribed to the unique free-standing and continous CPrGO–S network which has high specific surface area and good electrical conductivity. In addition, oxygen-containing groups on the partially reduced graphene oxide are beneficial to preventing the polysulfides from dissolving into electrolyte and can mitigate the ＂shuttle effect＂.
